Power Adjustment Of A Communication Link Based On State Disturbance Estimations

ABSTRACT

A communication device is provided that estimates one or more disturbance values associated with one or more components of the communication device, and adjusts the communication device to change a received power of the output signal. The communication device includes a transmitter having a seed laser configured to provide an amount of bandwidth for an output signal, an Erbium-doped fiber amplifier (EDFA) configured to increase an amplitude of the output signal, and a single mode variable optical attenuator (SMVOA) configured to decrease the amplitude of the output signal.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/251,392, filed Jan. 18, 2019, the disclosure of which isincorporated herein by reference.

BACKGROUND

Communication terminals may transmit and receive optical signals throughfree space optical communication (FSOC) links. In order to accomplishthis, such terminals generally use acquisition and tracking systems toestablish the optical link by pointing optical beams towards oneanother. For instance, a transmitting terminal may use a beacon laser toilluminate a receiving terminal, while the receiving terminal may use aposition sensor to locate the transmitting terminal and to monitor thebeacon laser. Steering mechanisms may maneuver the terminals to pointtoward each other and to track the pointing once acquisition isestablished. A high degree of pointing accuracy may be required toensure that the optical signal will be correctly received.

The mechanisms of communication terminals may vary physically due todifferences in operation over time. For example, mechanisms may becycled through large temperature ranges and experience significantlyvarying plant (mechanism) characteristics. Mechanisms may wear with use,which may change friction and viscosity characteristics. Mechanisms mayalso have components that reduce performance using traditional controlstechniques. In these situations, it may be difficult to compensate forthe variability caused by the changes in the components in order toobtain reliable operation of a communication terminal.

BRIEF SUMMARY

Aspects of the disclosure provide for a communication system. Thecommunication system includes one or more sensors configured to receivemeasurements related to a state of the communication system; atransmitter configured to transmit an outbound signal to a remotecommunication system; a receiver configured to receive an inbound signalfrom the remote communication system; and one or more processors incommunication with the one or more sensors, the transmitter, and thereceiver. The one or more processors are configured to receive, usingthe one or more sensors, one or more measurements related to the stateof the communication system during a first timeframe; receive, from theremote communication system, an indication of an amount of receivedpower at the remote communication system during the first timeframe;estimate a plurality of disturbance values to the communication systemfor the first timeframe and a second timeframe smaller than the firsttimeframe according to the one or more measurements and the indication,each disturbance value being an average amount of change in power over agiven timeframe associated with a set of components of the communicationsystem; and adjust a given component of the communication system fromthe set of components to cause a change in power of a signal to betransmitted from the communication system to the remote communicationsystem based on the plurality of disturbance values.

In one example, the one or more processors are configured to estimatethe plurality of disturbance values based on a first disturbance valueestimated by determining an average amount of change of the indicationover the second timeframe equal to or on the same order of the firsttimeframe; and a second disturbance value estimated by subtracting thefirst disturbance value from the received indication and thendetermining an average amount of change of the indication over a thirdtimeframe less than the second timeframe. In another example, the one ormore processors are configured to estimate the plurality of disturbancevalues based on the set of components associated with each disturbancevalue. In this example, the one or more processors are furtherconfigured to identify the set of components based on: a determinationthat a time constant for a variation of the set of components is a sameor similar value as the given timeframe for an estimated disturbancevalue; a determination that a detected change in the receivedmeasurements associated with the set of components is a likely cause ofan estimated disturbance value; or an identification of a known changein behavior of the set of components associated with a receivedmeasurement.

In a further example, the one or more processors are configured toadjust the given component by controlling the transmitter to increase ordecrease power of the outbound signal. In yet another example, thesystem is a free-space optical communication system; the transmitter isconfigured to transmit an optical outbound signal to the remotecommunication system; and the receiver is configured to receive anoptical inbound signal from the remote communication system. In a stillfurther example, the one or more processors are further configured toreceive an updated indication; estimate one or more updated disturbancevalues; and adjust the given component based on the one or more updateddisturbance values.

Other aspects of the disclosure provide for a method for adjusting acomponent of a communication device. The method includes receiving, byone or more processors of the communication device, one or moremeasurements related to a state of the communication device during afirst timeframe; receiving, by the one or more processors, an indicationof an amount of received power at a remote communication device duringthe first timeframe; estimating, by the one or more processors, aplurality of disturbance values to the communication device for thefirst timeframe and a second timeframe smaller than the first timeframeaccording to the one or more measurements and the indication, eachdisturbance value being an average amount of change in power over agiven timeframe associated with a set of components of the communicationdevice; and adjusting, by the one or more processors, a given componentof the communication device from the set of components to cause a changein power of a signal to be transmitted from the communication device tothe remote communication device based on the plurality of disturbancevalues.

In one example, estimating the plurality of disturbance values includesestimating a first disturbance value by determining an average amount ofchange of the indication over the second timeframe equal to or on thesame order of the first timeframe; and estimating a second disturbancevalue may by subtracting the first disturbance value from the receivedindication and then determining an average amount of change of theindication over a third timeframe less than the second timeframe. Inanother example, estimating the plurality of disturbance values includesidentifying the set of components associated with each disturbancevalue. In this example, identifying the set of components includesdetermining that a time constant for a variation of the set ofcomponents is a same or similar value as the given timeframe for anestimated disturbance value. Alternatively in this example, identifyingthe set of components includes determining that a detected change in thereceived one or more measurements associated with the set of componentsis a likely cause of an estimated disturbance value. Also optionally inthis example, identifying the set of components includes identifying aknown change in behavior of the set of components associated with areceived measurement.

In a further example, the method also includes receiving, by the one ormore processors, an updated indication; estimating, by the one or moreprocessors, one or more updated disturbance values; and adjusting, bythe one or more processors, a given component based on the one or moreupdated disturbance values.

Further aspects of the disclosure provide for a non-transitory, tangiblecomputer-readable storage medium on which computer readable instructionsof a program are stored. The instructions, when executed by one or moreprocessors of a first communication device, cause the one or moreprocessors to perform a method. The method includes receiving one ormore measurements related to a state of the first communication deviceduring a first timeframe; receiving an indication of an amount ofreceived power at a second communication device during the firsttimeframe; estimating a plurality of disturbance values to the firstcommunication device for the first timeframe and a second timeframesmaller than the first timeframe according to the one or moremeasurements and the indication, each disturbance value being an averageamount of change in power over a given timeframe associated with a setof components of the first communication device; and adjusting a givencomponent of the first communication device from the set of componentsto cause a change in power of a signal to be transmitted from the firstcommunication device to the second communication device based on theplurality of disturbance values.

In one example, estimating the plurality of disturbance values includesestimating a first disturbance value by determining an average amount ofchange of the indication over the second timeframe equal to or on thesame order of the first timeframe; and estimating a second disturbancevalue may by subtracting the first disturbance value from the receivedindication and then determining an average amount of change of theindication over a third timeframe less than the second timeframe. Inanother example, estimating the plurality of disturbance values includesidentifying the set of components associated with each disturbancevalue. In this example, identifying the set of components includesdetermining that a time constant for a variation of the set ofcomponents is a same or similar value as the given timeframe for anestimated disturbance value. Alternatively in this example, identifyingthe set of components includes determining that a detected change in thereceived measurements associated with the set of components is a likelycause of an estimated disturbance value. Also optionally in thisexample, identifying the set of components includes identifying a knownchange in behavior of the set of components associated with a receivedmeasurement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram 100 of a first communication device and asecond communication device in accordance with aspects of thedisclosure.

FIG. 2 is a pictorial diagram of components of the first communicationdevice and the second communication device in accordance with aspects ofthe disclosure.

FIG. 3 is a pictorial diagram of a network 300 in accordance withaspects of the disclosure.

FIG. 4 is a flow diagram 400 depicting a method in accordance withaspects of the disclosure.

DETAILED DESCRIPTION Overview

The technology relates to a communication system configured to adjustthe power of a communication link based on disturbances to thecommunication system. Power for a link should be adjusted to stay withina functional range of receiving sensors in order to provide continuousservice to users. In particular, power should be high enough for thesensors to detect incoming signals but not so high so as to oversaturatethe sensors in the communication system. Atmospheric fluctuations maycause the power received at a remote terminal to surge or drop. Thecommunication system may be able to decrease or increase the power tocounteract a surge or drop and maintain a constant or near constantreceived power at a remote communication device.

The features, described in more detail below, may provide for acommunication system that is able to maintain a communication link at amore consistent received power, even in variable environments. Byidentifying components that cause a given disturbance, adjustments maybe made that more efficiently address the disturbance over time. As aresult, system availability and data throughput over a communicationlink may be increased, and a tracking system may be able to maintain astable lock with higher percentage availability. The tracking system ofthe communication system may be operated more accurately such that lesspower is needed to maintain a lock on a communication link.

In addition, more accurate predictions may be made regarding overallperformance of the communication system and adjustments to thecommunication system. There may be less heat generation, so the overalltemperature of the system allows the components of the system to performmore optimally. The communication system may also have less waste ofpower and therefore have a longer operating lifetime.

Example Systems

FIG. 1 is a block diagram 100 of a first communication device 102 of afirst communication terminal configured to form one or more links with asecond communication device 122 of a second communication terminal, forinstance as part of a system such as a free-space optical communication(FSOC) system. For example, the first communication device 102 includesas components one or more processors 104, a memory 106, a transmitter112, a receiver 114, a steering mechanism 116, and one or more sensors118. The first communication device 102 may include other components notshown in FIG. 1.

The one or more processors 104 may be any conventional processors, suchas commercially available CPUs. Alternatively, the one or moreprocessors may be a dedicated device such as an application specificintegrated circuit (ASIC) or other hardware-based processor, such as afield programmable gate array (FPGA). Although FIG. 1 functionallyillustrates the one or more processors 104 and memory 106 as beingwithin the same block, the one or more processors 104 and memory 106 mayactually comprise multiple processors and memories that may or may notbe stored within the same physical housing. Accordingly, references to aprocessor or computer will be understood to include references to acollection of processors or computers or memories that may or may notoperate in parallel.

Memory 106 may store information accessible by the one or moreprocessors 104, including data 108, and instructions 110, that may beexecuted by the one or more processors 104. The memory may be of anytype capable of storing information accessible by the processor,including a computer-readable medium such as a hard-drive, memory card,ROM, RAM, DVD or other optical disks, as well as other write-capable andread-only memories. The system and method may include differentcombinations of the foregoing, whereby different portions of the data108 and instructions 110 are stored on different types of media. In thememory of each communication device, such as memory 106, calibrationinformation may be stored, such as one or more offsets determined fortracking a signal.

Data 108 may be retrieved, stored or modified by the one or moreprocessors 104 in accordance with the instructions 110. For instance,although the technology is not limited by any particular data structure,the data 108 may be stored in computer registers, in a relationaldatabase as a table having a plurality of different fields and records,XML documents or flat files.

The instructions 110 may be any set of instructions to be executeddirectly (such as machine code) or indirectly (such as scripts) by theone or more processors 104. For example, the instructions 110 may bestored as computer code on the computer-readable medium. In that regard,the terms “instructions” and “programs” may be used interchangeablyherein. The instructions 110 may be stored in object code format fordirect processing by the one or more processors 104, or in any othercomputer language including scripts or collections of independent sourcecode modules that are interpreted on demand or compiled in advance.Functions, methods and routines of the instructions 110 are explained inmore detail below.

The one or more processors 104 are in communication with the transmitter112 and the receiver 114. Transmitter 112 and receiver 114 may be partof a transceiver arrangement in the first communication device 102. Theone or more processors 104 may therefore be configured to transmit, viathe transmitter 112, data in a signal, and also may be configured toreceive, via the receiver 114, communications and data in a signal. Thereceived signal may be processed by the one or more processors 104 toextract the communications and data.

The transmitter 112 may include an optical transmitter, an amplifier,and an attenuator. As shown in FIG. 2, the transmitter 112 includes aseed laser 202 configured to provide an amount of bandwidth for anoutput signal, an Erbium-doped fiber amplifier (EDFA) 204 configured toincrease an amplitude of the output signal, and a single mode variableoptical attenuator (SMVOA) 206 configured to decrease the amplitude ofthe output signal. In addition, as shown in FIG. 1, the transmitter 112may be configured to output a beacon beam 20 that allows onecommunication device to locate another, as well as a communicationsignal over a communication link 22. The output signal from thetransmitter 112 may therefore include the beacon beam 20, thecommunication signal, or both. The communication signal may be a signalconfigured to travel through free space, such as, for example, aradio-frequency signal or optical signal. In some cases, the transmitterincludes a separate beacon transmitter configured to transmit the beaconbeam and one or more communication link transmitters configured totransmit the optical communication beam. Alternatively, the transmitter112 may include one transmitter configured to output both the beaconbeam and the communication signal. The beacon beam 20 may illuminate alarger solid angle in space than the optical communication beam used inthe communication link 22, allowing a communication device that receivesthe beacon beam to better locate the beacon beam. For example, thebeacon beam carrying a beacon signal may cover an angular area on theorder of a square milliradian, and the optical communication beamcarrying a communication signal may cover an angular area on the orderof a hundredth of a square milliradian.

As shown in FIG. 1, the transmitter 112 of the first communicationdevice 102 is configured to output a beacon beam 20 a to establish acommunication link 22 a with the second communication device 122, whichreceives the beacon beam 20 a. The first communication device 102 mayalign the beacon beam 20 a co-linearly with the optical communicationbeam (not shown) that has a narrower solid angle than the beacon beam 20a and carries a communication signal 24. As such, when the secondcommunication device 122 receives the beacon beam 20 a, the secondcommunication device 122 may establish a line-of-sight link with thefirst communication device 102 or otherwise align with the firstcommunication device. As a result, the communication link 22 a thatallows for the transmission of the optical communication beam (notshown) from the first communication device 102 to the secondcommunication device 122 may be established.

The receiver 114 includes a tracking system configured to detect anoptical signal. As shown in FIG. 2, the receiver 114 for the opticalcommunication system may include a multi-mode variable opticalattenuator 208 configured to adjust an amplitude of a received signal, aphotosensitive detector 210, and/or a photodiode 212. Using thephotosensitive detector 210, the receiver 114 is able to detect a signallocation and convert the received optical signal into an electric signalusing the photoelectric effect. The receiver 114 is able to track thereceived optical signal, which may be used to direct the steeringmechanism 116 to counteract disturbances due to scintillation and/orplatform motion.

Returning to FIG. 1, the one or more processors 104 are in communicationwith the steering mechanism 116 for adjusting the pointing direction ofthe transmitter 112, receiver 114, and/or optical signal. The steeringmechanism 116 may include one or more mirrors that steer an opticalsignal through the fixed lenses and/or a gimbal configured to move thetransmitter 112 and/or the receiver 114 with respect to thecommunication device. In particular, the steering mechanism 116 may be aMEMS 2-axis mirror, 2-axis voice coil mirror, or piezo electronic 2-axismirror. The steering mechanism 116 may be configured to steer thetransmitter, receiver, and/or optical signal in at least two degrees offreedom, such as, for example, yaw and pitch. The adjustments to thepointing direction may be made to acquire a communication link, such ascommunication link 22, between the first communication device 102 andthe second communication device 122. To perform a search for acommunication link, the one or more processors 104 may be configured usethe steering mechanism 116 to point the transmitter 112 and/or thereceiver 114 in a series of varying directions until a communicationlink is acquired. In addition, the adjustments may optimize transmissionof light from the transmitter 112 and/or reception of light at thereceiver 114.

The one or more processors 104 are also in communication with the one ormore sensors 118. The one or more sensors 118, or estimators, may beconfigured to monitor a state of the first communication device 102. Theone or more sensors may include an inertial measurement unit (IMU),encoders, accelerometers, or gyroscopes and may include one or moresensors configured to measure one or more of pose, angle, velocity,torques, as well as other forces. In addition, the one or more sensors118 may include one or more sensors configured to measure one or moreenvironmental conditions such as, for example, temperature, wind,radiation, precipitation, humidity, etc. In this regard, the one or moresensors 118 may include thermometers, barometers, hygrometers, etc.While the one or more sensors 118 are depicted in FIG. 1 as being in thesame block as the other components of the first communication device102, in some implementations, some or all of the one or more sensors maybe separate and remote from the first communication device 102.

The second communication device 122 includes one or more processors 124,a memory 126, a transmitter 132, a receiver 134, a steering mechanism136, and one or more sensors 138. The one or more processors 124 may besimilar to the one or more processors 104 described above. Memory 126may store information accessible by the one or more processors 124,including data 128 and instructions 130 that may be executed byprocessor 124. Memory 126, data 128, and instructions 130 may beconfigured similarly to memory 106, data 108, and instructions 110described above. In addition, the transmitter 132, the receiver 134, andthe steering mechanism 136 of the second communication device 122 may besimilar to the transmitter 112, the receiver 114, and the steeringmechanism 116 described above.

Like the transmitter 112, transmitter 132 may include an opticaltransmitter, an amplifier, and an attenuator. As shown in FIG. 2, thetransmitter 132 includes a seed laser 222 configured to provide anamount of bandwidth for an output signal, an EDFA 224 configured toincrease an amplitude of the output signal, and a SMVOA 226 configuredto decrease the amplitude of the output signal. Additionally, as shownin FIG. 1, transmitter 132 may be configured to output both an opticalcommunication beam and a beacon beam. For example, transmitter 132 ofthe second communication device 122 may output a beacon beam 20 b toestablish a communication link 22 b with the first communication device102, which receives the beacon beam 20 b. The second communicationdevice 122 may align the beacon beam 20 b co-linearly with the opticalcommunication beam (not shown) that has a narrower solid angle than thebeacon beam and carries another communication signal. As such, when thefirst communication device 102 receives the beacon beam 20 a, the firstcommunication device 102 may establish a line-of-sight with the secondcommunication device 122 or otherwise align with the secondcommunication device. As a result, the communication link 22 b, thatallows for the transmission of the optical communication beam (notshown) from the second communication device 122 to the firstcommunication device 102, may be established.

Like the receiver 114, the receiver 134 includes a tracking systemconfigured to detect an optical signal as described above with respectto receiver 114. As shown in FIG. 2, the receiver 114 for the opticalcommunication system may include a multi-mode variable opticalattenuator 228 configured to adjust an amplitude of a received signal, aphotosensitive detector 230, and/or a photodiode 232. Other componentssimilar to those pictured in the first communication device 102 may alsobe included in the second communication device 122. Using thephotosensitive detector 230, the receiver 134 is able to detect a signallocation and convert the received optical signal into an electric signalusing the photoelectric effect. The receiver 134 is able to track thereceived optical signal, which may be used to direct the steeringmechanism 136 to counteract disturbances due to scintillation and/orplatform motion.

Returning to FIG. 1, the one or more processors 124 are in communicationwith the steering mechanism 136 for adjusting the pointing direction ofthe transmitter 132, receiver 134, and/or optical signal, as describedabove with respect to the steering mechanism 116. The adjustments to thepointing direction may be made to establish acquisition and connectionlink, such as communication link 22, between the first communicationdevice 102 and the second communication device 122. In addition, the oneor more processors 124 are in communication with the one or more sensors138 as described above with respect to the one or more sensors 118. Theone or more sensors 138 may be configured to monitor a state of thesecond communication device 122 in a same or similar manner that the oneor more sensors 118 are configured to monitor the state of the firstcommunication device 102.

As shown in FIG. 1, the communication links 22 a and 22 b may be formedbetween the first communication device 102 and the second communicationdevice 122 when the transmitters and receivers of the first and secondcommunication devices are aligned, or in a linked pointing direction.Using the communication link 22 a, the one or more processors 104 cansend communication signals to the second communication device 122. Usingthe communication link 22 b, the one or more processors 124 can sendcommunication signals to the first communication device 102. In someexamples, it is sufficient to establish one communication link 22between the first and second communication devices 102, 122, whichallows for the bi-directional transmission of data between the twodevices. The communication links 22 in these examples are FSOC links. Inother implementations, one or more of the communication links 22 may beradio-frequency communication links or other type of communication linkcapable of travelling through free space.

As shown in FIG. 3, a plurality of communication devices, such as thefirst communication device 102 and the second communication device 122,may be configured to form a plurality of communication links(illustrated as arrows) between a plurality of communication terminals,thereby forming a network 300. The network 300 may include clientdevices 310 and 312, server device 314, and communication devices 102,122, 320, 322, and 324. Each of the client devices 310, 312, serverdevice 314, and communication devices 320, 322, and 324 may include oneor more processors, a memory, a transmitter, a receiver, and a steeringmechanism similar to those described above. Using the transmitter andthe receiver, each communication device in network 300 may form at leastone communication link with another communication device, as shown bythe arrows. The communication links may be for optical frequencies,radio frequencies, other frequencies, or a combination of differentfrequency bands. In FIG. 3, the communication device 102 is shown havingcommunication links with client device 310 and communication devices122, 320, and 322. The communication device 122 is shown havingcommunication links with communication devices 102, 320, 322, and 324.

The network 300 as shown in FIG. 3 is illustrative only, and in someimplementations the network 300 may include additional or differentcommunication terminals. The network 300 may be a terrestrial networkwhere the plurality of communication devices is on a plurality of groundcommunication terminals. In other implementations, the network 300 mayinclude one or more high-altitude platforms (HAPs), which may beballoons, blimps or other dirigibles, airplanes, unmanned aerialvehicles (UAVs), satellites, or any other form of high altitudeplatform, or other types of moveable or stationary communicationterminals. In some implementations, the network 300 may serve as anaccess network for client devices such as cellular phones, laptopcomputers, desktop computers, wearable devices, or tablet computers. Thenetwork 300 also may be connected to a larger network, such as theInternet, and may be configured to provide a client device with accessto resources stored on or provided through the larger computer network.

Example Methods

While connected, the one or more processors 104 of the firstcommunication device 102 and/or the one or more processors 124 of thesecond communication device 122 may adjust power to a communication linkwith a remote communication system as further described below. In FIG.4, flow diagram 400 is shown in accordance with aspects of thedisclosure that may be performed by the one or more processors 104and/or the one or more processors 124. While FIG. 4 shows blocks in aparticular order, the order may be varied and that multiple operationsmay be performed simultaneously. Also, operations may be added oromitted.

At block 402, the one or more processors 104 of the first communicationdevice 102 receive an indication of an amount of received power for acommunication link 22 from the second communication device 122 during afirst timeframe. The indication may be a relative received signalstrength indicator or other type of measurement. The indication may bereceived via an optical signal, a RF signal, etc. from the secondcommunication device 122. The indication may be received continually orat regular intervals, such as every 0.1 seconds or more or less. Eachindication may be stored in the memory 106 of the first communicationdevice. In one scenario, the first timeframe may be on the order ofmonths, weeks, or days, or more or less. In some implementations, theindication may include a first measurement related to a received powerof a beacon beam and a first measurement related to a received power ofa communication beam.

At block 404, the one or more processors 104 also receive measurementsrelated to a state of the first communication device 102 during thefirst timeframe. The measurements may be received from the one or moresensors 118 of the first communication device 102 and may include, forexample, orientation of the first communication device, frequency ofvibration of the first communication device, output power, altitude,humidity, temperature, etc. The measurements may be received continuallyor at regular intervals, such as every 0.1 seconds or more or less. Eachmeasurement may be stored in the memory 106 of the first communicationdevice.

At block 406, the one or more processors 104 estimate one or moredisturbance values to the first communication device 102 according tothe received indication and the received measurements. Each disturbancevalue may be an average amount of change in power over a giventimeframe. A first disturbance value may be estimated by determining anaverage amount of change of the indication over a second timeframe, forinstance which is equal to or on the same order of the first timeframe.The second timeframe may be selected according to a first time constantfor variation of a component of the first communication device 102. Thefirst time constant may be the amount of time over which a measurementrelated to the component changes by a predetermined factor, such as afactor of 1-1/e (or approximately 0.6321). The first time constant maybe known or may be determined using the received measurements. Inparticular, the first time constant may be a known or predicted timeconstant for a degradation, or decay, of the component. The secondtimeframe may be equal to the first time constant. For example, thesecond timeframe may be a month, which may be the time constant for adegradation of the photodiode detector, the EDFA and/or the seed laserby a factor of 1-1/e.

Then, a second disturbance value may be estimated by subtracting thefirst disturbance value from the received indication and thendetermining an average amount of change of the power over a thirdtimeframe that is less than the second timeframe. The third timeframemay be selected according to a second time constant for variation ofanother component of the first communication device 102. The second timeconstant may be the amount of time over which a measurement related tothe other component changes by the same predetermined factor, such as afactor of 1-1/e. The third timeframe may be equal to the second timeconstant. Additional disturbance values for additional timeframes may bedetermined in a similar manner.

Estimating the one or more disturbance values may include identifyingone or more components of the first communication device 102 to beassociated with each disturbance value. The identification of acomponent may include determining that a time constant for the variationof the component is a same or similar value as the timeframe for anestimated disturbance value. For instance, a known or predicted timeconstant for the degradation of the component may be the same or similarto the timeframe for the estimated disturbance value. The identificationof a component may also include determining that a detected change inthe received measurements associated with the component is a likelycause of an estimated disturbance value. For example, the detectedchange may occur in the same timeframe as the estimated disturbancevalue. In addition, the identification of a component may includeidentifying a known change in behavior of a component associated with areceived measurement, such as differences in an amount of output due toaltitude, temperature, humidity, or other type of environmentalmeasurement.

At block 408, the one or more processors 104 adjust a given component ofthe first communication device 102 to cause a change in power of acommunication signal output from the first communication device 102 overthe communication link 22 according to the one or more disturbancevalues. Adjusting the one or more components may include controlling thetransmitter 112 to increase or decrease power of the output signal. Forexample, the transmitter 112 may adjust the power of the output signalat a rate equal and opposite to a predicted amount of decrease due tothe one or more disturbances. The adjustment to the transmitter 112 maybe a power adjustment to the beacon beam, the communication signal, orboth. This power adjustment may be performed by using the SMVOA tocontrol an amount of the beacon beam that is fed into the EDFA and/oradjusting the output of the EDFA. In some examples, the power adjustmentmay be performed by reducing or increasing a number of channels in thecommunication signal or by adjusting protection mechanisms for aparticular receiver. Adjusting the one or more components may alsoinclude controlling the steering mechanism 116 to adjust a pointingdirection of the optical signal, adjusting a threshold in one or morealgorithms, or changing a photodetector amplifier gain electrically.

Alternatively, the one or more processors 104 may determine noadjustment is needed when no component is identified as being associatedwith the one or more disturbance values. No component may be identifiedwhen the disturbance to the received indication has characteristicsassociated with an obstacle between the first communication device 102and the second communication device 122. For example, thecharacteristics may include some fraction of the initial signal dropduring a fade was steeper than a threshold, the signal power has droppedbelow to a set minimum threshold, or the signal power has remained belowthe set threshold for a certain amount of time. The one or moreprocessors 104 may pause some operations related to the communicationlink to conserve energy while the obstacle is detected, determine whenan obstacle is gone, and resume operation.

In some implementations, the one or more processors 104 may also predicta future disturbance value associated with one or more components basedon the received measurements and/or predicted behavior of the one ormore components over time. Based on the future disturbance value, theone or more processors 104 may schedule adjustments to a given componentof the first communication device.

Unless otherwise stated, the foregoing alternative examples are notmutually exclusive, but may be implemented in various combinations toachieve unique advantages. As these and other variations andcombinations of the features discussed above can be utilized withoutdeparting from the subject matter defined by the claims, the foregoingdescription of the embodiments should be taken by way of illustrationrather than by way of limitation of the subject matter defined by theclaims. In addition, the provision of the examples described herein, aswell as clauses phrased as “such as,” “including” and the like, shouldnot be interpreted as limiting the subject matter of the claims to thespecific examples; rather, the examples are intended to illustrate onlyone of many possible embodiments. Further, the same reference numbers indifferent drawings can identify the same or similar elements.

1. A communication device, comprising: a transmitter including: a seedlaser configured to provide an amount of bandwidth for an output signal,an Erbium-doped fiber amplifier (EDFA) configured to increase anamplitude of the output signal, and a single mode variable opticalattenuator (SMVOA) configured to decrease the amplitude of the outputsignal; and one or more processors in communication with thetransmitter, the one or more processors being configured to: estimateone or more disturbance values associated with one or more components ofthe communication device, and adjust the communication device to changea received power of the output signal.
 2. The communication device ofclaim 1, wherein the one or more processors are configured to estimatethe one or more disturbance values according to an indication from aremote communication device and one or more measurements related to thecommunication device.
 3. The communication device of claim 2, whereineach disturbance value is an average amount of change in power over agiven timeframe.
 4. The communication device of claim 2, wherein adisturbance value of the one or more disturbance values is estimated bydetermining an average amount of change of the indication over atimeframe.
 5. The communication device of claim 2, wherein the one ormore processors are further configured to receive, using one or moresensors, one or more measurements related to a state of thecommunication device during a first timeframe.
 6. The communicationdevice of claim 5, wherein the one or more processors are furtherconfigured to receive, from the remote communication device, anindication of an amount of received power at the remote communicationdevice during the first timeframe.
 7. The communication device of claim6, wherein the one or more processors are configured to estimate the oneor more disturbance values for the first timeframe and for a secondtimeframe smaller than the first timeframe according to the one or moremeasurements and the indication, each disturbance value being an averageamount of change in power over a given timeframe associated with one ormore components of the communication device.
 8. The communication deviceof claim 7, wherein the one or more processors are further configured toreceive, using one or more sensors, one or more measurements related toa state of the communication device during the first timeframe.
 9. Thecommunication device of claim 7, wherein the one or more processors areconfigured to estimate the one or more disturbance values based on: afirst disturbance value estimated by determining an average amount ofchange of the indication over the second timeframe equal to or on a sameorder of the first timeframe; and a second disturbance value estimatedby subtracting the first disturbance value from the indication and thendetermining an average amount of change of the indication over a thirdtimeframe less than the second timeframe.
 10. The communication deviceof claim 9, wherein the one or more processors are further configured toidentify one or more components associated with each of the one or moredisturbance values.
 11. The communication device of claim 1, furthercomprising a receiver including: at least one of a photosensitivedetector and a photodiode, and a multi-mode variable optical attenuatorconfigured to adjust an amplitude of a received signal.
 12. Thecommunication device of claim 11, wherein the photosensitive detectorenables the receiver to detect a signal location and convert a receivedoptical signal into an electric signal using a photoelectric effect. 13.The communication device of claim 1, wherein, to adjust thecommunication device to change the received power of the output signal,the one or more processors are configured to adjust one or more of apointing direction of the optical signal, a threshold in one or morealgorithms, or a photodetector amplifier gain.
 14. The communicationdevice of claim 13, wherein the one or more processors are configured toadjust the pointing direction of the optical signal using a steeringmechanism, and wherein the steering mechanism is a MEMS 2-axis mirror.15. The communication device of claim 13, wherein the one or moreprocessors are configured to adjust the pointing direction of theoptical signal using a steering mechanism, and wherein the steeringmechanism is a 2-axis voice coil mirror.
 16. The communication device ofclaim 13, wherein the one or more processors are configured to adjustthe pointing direction of the optical signal using a steering mechanism,and wherein the steering mechanism is a piezo electronic 2-axis mirror.17. The communication device of claim 1, wherein the one or moreprocessors are further configured to determine that no adjustment to thecommunication device is needed when none of the one or more componentsof the communication device is identified as being associated with theone or more disturbance values.
 18. The communication device of claim17, wherein the one or more processors are configured to determine thatnone of the one or more components of the communication device isidentified as being associated with the one or more disturbance valueswhen an indication from a remote communication device hascharacteristics associated with an obstacle between the communicationdevice and the remote communication device.
 19. The communication deviceof claim 17, wherein the one or more processors are further configuredto pause one or more operations of the communication device for a periodof time.
 20. The communication device of claim 1, wherein the one ormore disturbance values includes a future disturbance value based onpredicted behavior of the one or more components of the communicationdevice; and wherein the one or more processors are further configured toschedule a point in time to adjust the communication device to changethe received power of the optical signal based on the future disturbancevalue.